Potassium voltage-gated channel subfamily Q member 2-5 (KCNQ2-5)

The KCNQ2-5 potassium channels, commonly referred to as Kv7.2–Kv7.5 channels, are a family of voltage-gated potassium channels predominantly expressed in the nervous system[1][7]. These channels are crucial for the generation of the neuronal M-current, a non-inactivating current that stabilizes the membrane potential and acts as a brake on neuronal excitability[7][8]. The canonical architecture is a tetramer formed by KCNQ α subunits (each with six transmembrane segments: S1–S4 for voltage sensing, S5–S6 for forming the pore)[1][5]. Molecular interactions with phosphatidylinositol 4,5-bisphosphate (PIP₂) are essential for their proper gating[5]. KCNQ2–KCNQ5 channels are important therapeutic targets for seizure disorders, neuropathic pain, and other hyperexcitability conditions[2][4][5][6]. Drugs such as retigabine act as positive allosteric modulators, binding to a conserved tryptophan (Trp) in the channel pore, leading to enhanced channel opening at more negative membrane potentials and thereby reducing neuronal firing[2][6]. Mutations in KCNQ2 and KCNQ3 are a common cause of early-onset epilepsy syndromes, and functional augmentation of these channels is a validated antiepileptic strategy[7][8]. Therapeutically, safety issues with KCNQ channel modulators include CNS effects and, for some drugs like retigabine, pigment changes and cardiac risks[4]. Genetic or acquired dysfunction of these channels is linked to epilepsy and other neurodevelopmental or neuropsychiatric disorders[8].

Other names

Kv7.2–Kv7.5M-channelKCNQ channelVoltage-gated potassium channel subfamily Q (Kv7)

Positive allosteric modulation (channel activation); Stabilization of open channel conformation; Negative shift in voltage dependence of activation; Acceleration of channel opening and deceleration of closure